Range anxiety, as described by Mr. Weber, is the nagging worry that the electric vehicle you are driving is running out of battery charge.

I wonder how many people experience the same anxiety getting on a plane with their notebook, knowing they have a project or an inbox full of email to get through (or better still, five episodes of Lost to catch-up on). Not me. I’ve got a Dell XT Tablet with the extended battery. OK, makes my notebook a little thicker and heavier but I rarely run out of juice. It’s brilliant.